Luminaire device

ABSTRACT

A luminaire including a lamp, reflector, collimator and optional waveguide. The waveguide can be solid or hollow or include several serially-arranged total internal reflection (TIR) components for redirecting light that has entered the waveguide. In one embodiment, the TIR components are prisms, but are provided without metallized coatings thereby significantly reducing manufacturing costs. In another embodiment, components are arranged in a vertical orientation such that light is directed downward through a collimator or upward, either directly from the lamp or as a result of reflection from the reflector.

[0001] This application claims the benefit of U.S. ProvisionalApplication No. 60/409,269, filed Sep. 10, 2002, which is hereinincorporated by reference in its entirety.

BACKGROUND

[0002] 1. Field of the Invention

[0003] The present invention is directed to improvements in luminairedevices. More particularly, the present invention is directed to devicesand methods for directing light in certain directions and/or restrictinglight from emanating in certain directions using unique combinations ofreflectors, collimators, refractive media, waveguides, and TotalInternal Reflection (TIR) components.

[0004] 2. Background of the Invention

[0005] There are ongoing efforts to improve upon existing luminairedevices in view of standards such as ISO 5035/7, which require, amongother things, restricting light emanating from a luminaire to between 45and 85 degrees relative to the ceiling-normal. Light rays limited insuch a fashion reduce glare in the vicinity of computer screens, forexample, thereby decreasing eyestrain and fatigue on office workers and,as a result, increasing their productivity.

[0006] Well-known luminaires include those described by U.S. Pat. No.5,237,641 and U.S. Pat. No. 6,335,999, but the luminaire structuresdescribed in those patents have complicated structures or have othershortcomings that have yet to be addressed in the art.

SUMMARY OF THE INVENTION

[0007] The present invention is directed to improvements to and uniqueconfigurations for luminaire devices that provide light that is incompliance with standards such as ISO 5035/7, which require, among otherthings, that light emanating from a luminaire be restricted within anangular envelope with respect to a ceiling-normal. In a first embodimentof the present invention, a luminaire device includes a lamp such as atubular florescent bulb that is mounted in a holder and is partiallysurrounded on an underside thereof by a curved reflector. The reflectormay be smooth or multi-faceted. To one side of the lamp is a collimator.Light rays from the lamp are directed directly upward, directly downwardtowards the curved reflector, and towards the collimator either directlyor by reflection from the curved reflector. Generally speaking, most ofthe light emanating from the lamp is directed upward either directly orby reflection. The remaining light falls on an input side of thecollimator, which acts to orient the rays of light falling on the inputside of the collimator. Adjacent the output side of the collimator are aplurality of serially-arranged Total Internal Reflection (TIR)components that operate to capture the light output from the collimatorand redirect the light downward (or generally away from the luminairedevice depending on the orientation thereof).

[0008] In accordance with a fundamental principal of the presentinvention, a substantial portion of the light that falls upon an inputside of a first serially-arranged TIR component is reflected downwardand away from the luminaire. Any leakage of light (i.e., light that isnot reflected as a result of TIR within the first serially-arranged TIRcomponent) falls upon an input side of a second or successive TIRcomponent.

[0009] By using a succession of TIR components, it is possible tomanufacture an efficient luminaire device without expensive andcomplicated metallized coatings on TIR components. That is, by employingtwo or more serially-arranged TIR components (which can be inexpensivelymanufactured, as for example via injection molding an optical-gradepolymer such as acrylic), it is still possible to ensure that virtuallyall of the light that passes through the collimator is redirecteddownward in a desirable fashion, e.g., in accordance with the ISOstandard, without having to rely on expensive metallized coatings on theTIR components.

[0010] In one variation of the first embodiment of the present inventionthe serially-arranged TIR components comprise standard prisms that areformed integrally with one another or are formed of individualcomponents that are mounted on a common substrate. In another variant ofthe first embodiment of the present invention, the TIR componentscomprise serially-arranged solid sawtooth waveguides. In still anothervariant of the first embodiment of the present invention, a symmetricalluminaire is provided in which lamps and reflectors are located oneither side of a luminaire waveguide structure and the TIR componentsare arranged opposite one another in a “mirror image-like” fashion.

[0011] In yet another variant, the curved reflector partiallysurrounding the lamp is augmented by a refractive medium thereby makingit possible to reduce the overall size of the reflector or reflectors.

[0012] In a second embodiment of the present invention, the input andoutput sides of a collimator are arranged such that light passesvertically through the collimator such that the need for a waveguide(and even TIR components in some cases) may be reduced or eveneliminated. In a preferred implementation of the second embodiment, alight control film is provided at either the input or output of thecollimator (or both) to preclude direct view of the lamp and/or todiffuse light.

[0013] In a third embodiment of the present invention a solid waveguidehaving a sawtooth pattern on a hypotenuse side thereof is providedadjacent the output of the collimator. In accordance with thisembodiment of the present invention, the individual facets of thesawtooth feature of the waveguide reflect light received from thecollimator and capture and redirect leakage light that might leakthrough facets closer to the output of the collimator.

[0014] In a fourth embodiment of the present invention, a luminairedevice with a hollow cavity waveguide is provided. This embodimentpreferably includes an uncoated sawtooth film that is used as a lightextraction feature.

[0015] In a fifth embodiment of the present invention and one that isrelated to the fourth embodiment, a solid acrylic slab is positionedadjacent a portion of an output side of a collimator and extends apredetermined distance into a hollow cavity waveguide of a luminaire.The slab can be comprised of any material that has refractivecharacteristics sufficient to “push” light further down the waveguidethereby improving uniformity of light distribution over the length ofthe luminaire.

[0016] The foregoing embodiments and other features and attendantadvantages of the present invention will be fully understood byreferring to the following detailed description in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017]FIGS. 1 and 2 show an element of a first embodiment in accordancewith the present invention.

[0018]FIG. 3 illustrates results from a theoretical experiment modelingthe first embodiment of the present invention.

[0019]FIG. 4 shows a variant of the first embodiment of the presentinvention including solid sawtooth waveguides.

[0020]FIG. 5 shows still another variant of the first embodiment of thepresent invention.

[0021]FIG. 6 shows a curved reflector including a refracting medium inaccordance with the present invention.

[0022]FIG. 6A shows a variation of the reflector shown in FIG. 6,including a light pipe to reduce or eliminate TIR reflections back to anadjacent lamp.

[0023] FIGS. 7A-7E show features of a second embodiment according to thepresent invention.

[0024]FIGS. 8A and B show a variant of the second embodiment of thepresent invention.

[0025] FIGS. 9-11 show an exemplary implementation of the presentinvention for which performance results were generated usingcomputerized modeling techniques.

[0026]FIGS. 12 and 13 show graphical results of the modeled exemplaryimplementation of FIGS. 9-11.

[0027] FIGS. 14-16 illustrate more detailed features of a diffusionscreen disposed proximate an output end of a collimator in accordancewith the present invention.

[0028]FIG. 17 shows an exemplary implementation of the present inventionthat incorporates a circular fluorescent bulb.

[0029]FIGS. 18A and 18B illustrate a third embodiment of the presentinvention.

[0030]FIG. 19 shows a fourth embodiment of the present invention.

[0031]FIG. 20 shows a fifth embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0032] First Embodiment

[0033]FIGS. 1 and 2 show orthogonal views of an element of a firstembodiment according to the present invention in which a tubular lamp100 is located within a concave portion of a curved reflector 105.Adjacent to lamp 100 is a collimator 110 that receives light that is notdirected upward. The element of FIGS. 1 and 2 is serially arranged in alinear array to span the length of the tubular fluorescent lamp. Itshould be understood by those skilled in the art that the term“collimator” is used herein to encompass either a rectangularcross-section hollow collimator array or a triangular hollow collimatorarray (the latter described in U.S. Pat. No. 6,428,198). A “collimator”as used herein is also intended to encompass either a hollow collimatoror a solid collimator, the latter being comprised of alight-transmitting refractive medium—typically a polymer material. Anarray of solid collimators can comprise elements that are much smallerthan those of a hollow collimator thereby making it possible to make anarray of solid collimators much thinner than an array of hollowcollimators. Arrays of these smaller collimators are preferablytwo-dimensional arrays in order to capture the same solid angle of lightflux projected from the lamp as that captured by the one-dimensional(linear) array of larger collimators. Arrays of smaller solidcollimators can be fabricated by photo-lithography or by a moldingprocess. Arrays of larger hollow collimators can be formed fromspecularly reflecting sheet metal, such as produced by MaterialSciences, Inc., (Elk Grove Village, Ill.) going by the trade nameSpecular+.

[0034] Light that enters collimator 110 is directed substantiallyhorizontally (to the right in FIG. 1) towards at least twoserially-arranged Total Internal Reflection (TIR) components. In thecase of FIG. 1, three prisms 125 a, 125 b and 125 c are arranged insuccession and parallel to each other as shown also in FIG. 2. Prisms125 a, 125 b, 125 c may be formed integrally with another or may beindividual components that are mounted on a common substrate (notshown). Preferably, a flat reflector 130 is positioned above theserially-arranged TIR components 125 a-c to force substantially all ofthe light rays that have passed through collimator 110 through thesuccessive TIR components.

[0035] More specifically, rays 115 emanating from lamp 100 are directedupward or are reflected off of curved reflector 105 towards the ceilingof a room in which the luminaire structure is located. On the otherhand, rays 117 are reflected or are directed directly into collimator110, which collimates the rays and causes them to fall on a first sideof prism 125 a. While most of the light entering prism 125 a isdeflected downward (ray 128) in accordance with TIR principles, somelight, indicated by ray 118, leaks through the hypotenuse side of prism125 a. This leakage falls on a side of second prism 125 b, such thatalmost all of the light that passes through collimator is ultimatelydeflected down in compliance with the angle requirements of ISO 5035/7.Yet another prism, 125 c, or still additional prisms, can be employedserially as shown to deflect any light that might leak through thesecond or successive TIR components. Thus, in accordance with aprinciple of the present invention, substantially all of the light thatis not directed upward is directed first through a collimator and thendownward in a desirable fashion.

[0036] One significant advantage of this first embodiment (as well asother embodiments described below) is that there is no need (or areduced need) for metallized coatings on certain light distributingoptics (such as TIR components), thereby resulting in significant costsavings. In the case of prisms, such metallized coatings are typicallylocated on the hypotenuse of the prism. In accordance with theprinciples of the present invention, it is possible to eliminate thesecoatings by using the total internal reflection (TIR) properties ofsuccessive optics to direct an incident light beam in the desiredfashion.

[0037] It is noted that an overall specular enclosure (only one piece,130, is shown) may be desirable (or necessary in certain applications)to guide the rays from one optic to the next.

[0038] In one theoretical experiment on a luminaire in accordance withthis first embodiment, carried out with a software package known as ASAPPro (Breault Research Organization, Tucson, Ariz.), performance targetswere set as follows:

[0039] a) an overall efficiency of 80% (% of the lamp's light outputthat is output by the luminaire)

[0040] b) 80% of the luminaire's light output to be directed upward(i.e. Up Flux)

[0041] c) 20% of the luminaire's light output to be directed downward(i.e. Down Flux)

[0042] The results from this theoretical experiment, in which a tandemarrangement of TIR components was used, are shown in FIG. 3.

[0043]FIG. 4 shows a variant of the first embodiment wherein sawtoothwaveguides 405 a, 405 b are employed as the serially-arranged TIRcomponents. The lamp and adjacent collimator are not shown, but would bearranged to the left of the TIR components in FIG. 4. As illustrated,light rays that leak through any individual “tooth” in the firstsawtooth waveguide can be picked up by the second sawtooth waveguide anddeflected downward. Alternatively, the light rays that leak through canbe reflected from mirror surface 210 before being picked up by thesecond sawtooth waveguide and deflected downward. Accordingly, thisarrangement generates a down light directional distribution that is incompliance with a standard such as ISO 5035/7. One advantage of thisvariant is that Light flux density at the waveguide exit ports is spreadover a larger area than that of the standard prisms shown in FIG. 3thereby reducing glare from the down-light projected from the waveguideexit ports.

[0044]FIG. 5 shows still another variant of the first embodiment whereinthe serially-arranged TIR components are employed in an overall fixtureincluding a hanger 501 and two opposing pairs of serially-arranged TIRcomponents 405 a, 405 b and 405 c, 405 d. Opposing lamps 100, curvedreflectors 105 and collimator arrays 110 are also provided. Thisarrangement provides an aesthetically balanced fixture while throwingtwice as much light as a single lamp configuration. Consistent with theprinciples of the first embodiment, light from lamps 100 is eitherdirected upward or falls on the respective collimators. The light thatpasses through the collimators falls on a first TIR component and anyleakage from the first TIR component is applied to a second orsuccessive TIR component such that leakage out of a last TIR componentis insignificant.

[0045] As shown, the overall fixture or luminaire includes a reflector130 (a portion only of which is visible in FIG. 5) to direct TIR leakagerays back into the individual TIR components. Preferably, the TIRcomponents are uncoated thereby reducing the cost associated withmanufacturing the luminaire.

[0046] The dimensions of curved reflector 105 are typically a functionof the size of lamp 100 and the overall dimension of the luminairedevice. FIG. 6 shows one way of reducing the size of reflector 105 suchthat the luminaire can be accommodated in smaller spaces and to allowmore luminaires to be adjacent each other in a given space. Forsimplicity, collimators and the serially-arranged TIR components are notshown.

[0047] Referring to FIG. 6, a transparent refractive medium 605 ismounted on reflector 105 a (reflector 105 is shown by a dotted line).Transparent refractor 605 includes a curved reflective surface 606, afirst flat surface 607 facing lamp 100, and a second flat surface 608facing generally outward from reflector 105 a. Transparent refractor 605is advantageously composed from a solid refractive medium, such as glassor plastic.

[0048] A light ray 602 from lamp 100 entering transparent refractor 605is refracted normal to curved reflective surface 606 and propagates bytotal internal reflection until exiting transparent refractor 605 viasecond surface 608.

[0049] The refractive medium makes it possible to alter the shape of therequired reflective surface, comprising reflector 105 a and curvedreflector surface 606, resulting in an assembly that is more compactthan reflector 105. As shown in FIG. 6, the vertical span of thereflector is reduced while allowing no rays entering the refractivemedium to be directed back to the lamp surface. Although described inconnection with this first embodiment, the use of a refractive mediumconsistent with the above description can be employed in any embodimentdescribed herein that incorporates a curved or multi-faceted reflectorthat surrounds a lamp.

[0050]FIG. 6A shows a variation of the assembly depicted in FIG. 6. Inthis configuration, refractive medium 605 is given a slanted orientationcompared with that of FIG. 6. Also, a rectangular light pipe 625 hasbeen added to second surface 608. As shown by the several rays in FIG.6A, light that might otherwise reflect back to lamp 100 is preventedfrom doing so. Ideally, refractive medium 605 and rectangular light pipe625 comprise a monolithic structure. However, the curved surface ofrefractive medium 605 is preferably mirror coated to prevent light formleaking through. Other flat surfaces of refractive medium 605 and lightpipe 625 preferably remain uncoated, unless the coating is, for example,an anti-reflection coating.

[0051] Second Embodiment

[0052] FIGS. 7A-7E show features of a second embodiment according to thepresent invention. FIG. 7A illustrates the basic configuration of thissecond embodiment, which includes a lamp 100 (mounted as desired in alamp holder) and hollow collimators 110, which preferably comprisetapered surfaces having a specular coating thereon (although solidcollimators could also be employed). Side reflectors 305 are preferablyprovided to cap collimators 110 and to prevent direct view of lamp 100.In addition, a pre-collimator optional light control film 310 can beemployed to preclude direct-view of lamp 100 through collimators 110.Such films can be engineered diffusers or prismatic structures as isknown in the art. Further, while optional film 310 is shown parallel tothe input apertures of collimators 110, it can also be tilted or formedto provide the desired effect.

[0053]FIG. 7B shows another configuration in which angled sidereflectors 307 are provided adjacent to lamp 100, instead of the flatside reflectors shown in FIG. 7A. FIG. 7C shows yet anotherconfiguration according to the second embodiment. Here, curvedreflectors 105 take the place of both the flat reflectors or angledreflectors shown in FIGS. 7A and 7B. FIG. 7D shows two alternativeadditional features including (i) the possibility of arranging two ormore modular luminaire units together in a single fixture and (ii)employing an optional post-collimator light control film or diffusionscreen 320 to add aesthetic qualities to the fixture and/or to provideadditional light control. Diffuser screen 320 is described more fullybelow.

[0054]FIG. 7E depicts how a post-collimator light control film 320 (e.g.a fresnel structure, prism/lens array, etc) might be located at adistance away from the output of collimator 110, while stillintercepting substantially all light exiting collimator 110. Thisfunctionally reduces the surface luminance of the luminaire by spreadingthe lumens exiting collimator 110 over a larger area. For someonelooking directly up at the fixture, the configuration of FIG. 7E wouldbe perceived as having a softer glow than the configuration shown inFIGS. 7A-C. Such post-collimator sheet technology may be available fromNorton Industries (Lakewood, Ohio) or Reflexite (Avon, Conn.).

[0055]FIGS. 8A and 8B show a variant of the second embodiment wherein acollection of TIR components, in this case prisms 701, 703 is arrangedbeneath collimator 110. In FIG. 8A some portion of the light exitingcollimator 110 avoids prisms 701 altogether due to a gap 705 that isprovided between some of the prisms 701. Other light is captured by thepair of prisms 703 having at least a portion thereof directly in linewith the output of collimator 110. Light captured by these prisms isinternally reflected and passed to the adjacent serially-arrangedprisms, whereby light is transmitted downward in the same mannerdescribed earlier, including the principles of capturing leakage andpassing the same to successive TIR components. Note that depending uponthe refractive index of prisms 703 and the divergence exiting collimator110, some light may leak through the hypotenuse of prisms 703 (notshown).

[0056]FIG. 8B is very similar to the configuration depicted in FIG. 8Aexcept that gap 705 is removed such that substantially all of the lightexiting collimator 110 is passed to at least one prism 703, therebycausing the light to be passed to the remaining serially-arranged TIRcomponents 701. Note that depending upon the refractive index of prisms703 and the divergence exiting collimator 110, some light may leakthrough the hypotenuse of prisms 703 (not shown).

[0057] This second embodiment shows a variety of features not includedin the first embodiment, namely:

[0058] Vertical orientation of the collimators 110 thereby eliminatingthe need for a relatively large waveguide to extract light and to directit downward;

[0059] Addition of a pre-collimator light control structure to avoid adirect view of the lamp through the collimator;

[0060] Relatively simple modular design as shown, for example, by FIG.6D;

[0061] Addition of light control film 320 to widen the luminous regionof the luminaire to generate a superior aesthetic appearance. (The sameamount of light projected from a substantially smaller area has aconsiderably higher luminance, which is less aesthetically pleasing andwhich can produce disturbing glare reflections from the objectsilluminated); and

[0062] The use of several commercially-available off-the-shelf productsthat can be used as an alternative to Light Control Film (e.g. 3M's BEFfor the pre-collimator light control film, Norton Industries orReflexite for post-collimator prismatic sheets, Material SciencesSpecular+reflector material).

[0063] It is also possible to replace curved reflector 105 with amulti-faceted curved reflector like that shown in FIGS. 9-11. Such aluminaire combines a hollow lenticular faceted mirror for projectingup-light flux with one, or an array of, square cross-section taperedhollow tubular reflectors (collimators) for projecting down-light flux.The faceted mirror preferably includes a cusp below the lamp to bringdownward-projected light from the lamp around the lamp and upward towardthe ceiling. The mirror facets disposed around the lamp are preferablyangled such that lamp light reflections back to the lamp surface aretotally, or at least substantially, avoided. This both maximizes lightextracted from the lamp and minimizes heat retention by the luminaire.The array of tapered hollow tubular mirror cavities (e.g., collimators)forms compartments within the faceted mirror and distinct from it.Accordingly, the mirror cavities are devoid of cusp reflector mirrors.Each tubular mirror cavity at least partially collimates the down lamplight flux it intercepts and projects it downward toward the floor.Preferably, the mirror surfaces have a specular reflectance of 90%, orgreater. Of course, as the width of the mirror facets approaches zero,the lenticular mirror around the fluorescent lamp becomes a continuouscurve, which will then look like curved reflector 105. Dimensions (ininches) of the several components as shown in FIGS. 9-11 are:

[0064] AA: 1.0153

[0065] BB: 1.0392

[0066] CC: 2.9244

[0067] DD: 0.4089

[0068] EE: 0.2255

[0069] FF: 0.7179

[0070] GG: 0.630

[0071] Width of each facet: 0.280

[0072] These dimensions are exemplary only and are not meant to limitthe scope of this invention.

[0073]FIGS. 12 and 13 are graphical output results from an ASAPexecution run on a file that modeled the implementation of amulti-faceted curved reflector luminaire in accordance with theembodiment shown in FIGS. 9-11. The performance results are set forthimmediately below and the input file on which the analysis was based isset forth thereafter in Appendix A.

[0074] Performance Results Object Rays Flux  0 17  0.850000E−02 46161931 78.5146 UP_DET 47 4  0.182994E−02 TUBE1 48 1  0.475000E−03 TUBE251 38047 16.8460 DOWN_DET TOTAL 200000 95.3714

[0075] Specular Reflectance of all Mirror Surfaces=95%

[0076] Total Lamp Flux Emitted=100%

[0077] Up-Light Flux=78.5%

[0078] Down-Light Flux=16.85%

[0079] Up/Down-Light Ratio=4.66

[0080] Overall Efficiency=95.4%

[0081] As mentioned above, a diffusion screen 320 may be disposed belowcollimator 110. Diffusion screen 320 is preferably arranged or selectedto at least one of:

[0082] Capture the down light over an area larger than that of an exitport aperture;

[0083] Project captured rays from each area element of the capture areaover a specified range of down angles relative to the floor normal; or

[0084] Perform these functions with minimal light losses comprising onlyfresnel reflection losses at the input and output surfaces of diffusionscreen 320 and slight internal light absorption by the refractive mediumof diffusion screen 320.

[0085] An embodiment of a luminaire/diffusion system is shown in FIG.14. As before, the luminaire comprises a tubular (or lenticular)fluorescent lamp 100, an up-light projecting hollow lenticular cuspreflector disposed around lamp 100, a linear array of hollow collimatingmirror cavities 110 arranged below the tubular lamp and along itslength, and a screen or light collimating and diffusing element 320positioned below and along the hollow mirror cavity array.

[0086] Collimator/diffuser 320 is preferably a thin refractive elementwith top and bottom surfaces having lenticularly structured features.The lenticular center of the top surface directly below the linear arrayof hollow mirror cavities preferably has a conventional cylindrical lenssurface 325. Disposed adjacent to and on both sides of cylindrical lens325 is a lenticular sawtooth structure 328. Each sawtooth featurepreferably comprises a vertical light input facet and a hypotenusefacet. A light ray 340 projected from collimator 110 enters each of thevertical facets, is refracted into the diffuser medium, undergoes atotal internal reflection (TIR) by a hypotenuse facet, and is therebycollimated to propagate vertically downward toward the bottom surface339 of screen diffuser 320. The slope angle of the hypotenuse facet ispreferably engineered to collimate ray 340 from the center of the exitport aperture of hollow collimator 110. Also, to prevent light from theexit port aperture from falling directly on any of the hypotenusefacets, these facets preferably have maximum slope angles 342 a, 342 b,342 c relative to vertical that may not be exceeded lest light from theexit port entering that facet be refracted in unwanted directions thatdeviate too far from collimated vertical propagation.

[0087] As sawtooth facet positions approach the vertical centerline ofcylindrical lens 325, the hypotenuse facet angles will not be able tomeet the collimation criterion and the slope angle limitationsimultaneously. This will set a limit for the maximum distance of theboundary between the sawtooth facet arrays and the cylindrical lensedges and, thereby, will determine the minimum size of the cylindricallens.

[0088] It is advantageous to minimize the size of lens 325 to minimizeits thickness (compactness), weight, and aberrations. Accordingly, thesawtooth arrangement shown in FIG. 16 is a preferred implementation ofthis aspect of the present invention. It minimizes lens size byproviding an additional degree of freedom to the vertical sawtoothfacets by allowing their slope to vary from vertical. Accordingly, byengineering the hypotenuse facet slope and the corresponding verticalfacet slope variation, it becomes possible to bring properly functioningsawtooth facets closer to the lens center. This brings the lens edgescloser together and, thereby, reduces the size of the cylindrical lenssection.

[0089] The facet slope engineering process adjusts each hypotenuse facetslope toward the vertical and the rotates the corresponding verticalfacet slope in the same direction as this hypotenuse facet slopeadjustment rotation. The resulting facet configuration increases thedraft angle of the facets that were vertical prior to their slopeadjustment. This increases the draft angles of the sawtooth featuresand, thereby, enhances the mold release process. As is known in the art,the molding processes for different materials each have a minimum draftangle below which the mold release process becomes difficult oruntenable. For example, a typical specification for compression moldingacrylic is for a draft angle equal to, or greater than, 3 degrees.

[0090] Also, by adjusting hypotenuse facet slope angles toward thevertical allows sawtooth features to exist closer to the lens surfacecenterline without causing their hypotenuse facets to have a direct viewof the hollow collimator exit port apertures. This minimizes thecylindrical lens section size, thickness, and weight.

[0091] Note that light from lamp 100 may enter hollow collimator 110 atan angle approaching 90 degrees from vertical and project from its exitport aperture at a maximum angle approaching (for example) 60 degrees.(As defined here, collimation occurs when the limits of the outputangles of an element are less than those of its input angles.)

[0092] Light projected from the array of hollow collimator exit portsdiverges and is captured by the lenticular diffuser element 320suspended at a distance below it. The diverging beams projected downwardfrom each individual hollow collimator 110 may have substantial angularsymmetry about its axis. However, the linear array of individual hollowcollimators preferably includes a lenticular structure in the diffuserelement they illuminate because the individual diverging beams projectedfrom the array cross each other before they enter the diffuser.Accordingly, if a diffuser area element has structure that operates inthe cross-lenticular direction, it will receive light incident fromdifferent directions in vertical planes parallel to the lenticulardirection from a number of different hollow collimator elements of thearray. Owing to these multi-directional light inputs, sawtooth featureshaving cross-lenticular structure cannot project light from onedirectional input in a desired direction without also misdirecting lightincident from other different directions. This establishes the need forthe structured features of the diffuser to be lenticular with a lengthdimension parallel to the direction of the array.

[0093] The function of the collimator and diffuser element 320 comprisestwo separate actions. The top surface collimates light from the hollowcollimators 110 in planes normal to the length direction of thelenticular features. The bottom surface diffuses the collimated light.The result produces illumination that may have angular projectionproperties similar to those from the hollow collimators. However, sincethe area of the diffuser element 320 exceeds that of the combined areasof the hollow collimator exit port apertures, its luminance is reducedand thereby generates less glare.

[0094] The isometric view of FIG. 15 illustrates thecollimation/diffusion process and the relationship of the elements ofthis process. FIG. 15 shows how a light beam of substantial solid angleis projected toward the collimator and diffuser element 320 from eachexit port aperture of a linear array of hollow collimator elements 110.Two typical rays 380, 381 are shown, each within one of these beams andeach propagating from an exit port aperture to a corresponding areaelement 385, 386 on the top surface of the collimator and diffuserelement 320. The lenticular feature within each area element 385, 386which would generally be either a cylindrical lens surface or thehypotenuse facet of a sawtooth element, collimates the rays 388, 389 andtransmits them to corresponding area elements 390, 391 on the bottomsurface of the collimator and diffuser element. The lenticular diffusionfeatures 339 on the bottom surface and within each area element 390, 391project rays intercepted by area elements 390, 391 into beams 395, 396of similar solid angle to those projected from each exit port aperture.

[0095] Top Surface Collimation Action:

[0096] The cylindrical lens section preferably has a focal length equalto its distance below the hollow collimator exit port. Accordingly, itcollimates the light it intercepts and projects it vertically downward.As previously mentioned, this collimation exists in planes normal to thelength of the cylindrical lens section. The divergence of the beam thuscollimated is approximately equal to plus or minus the arc tangent of[half the span of a hollow collimator exit port divided by the cylinderlens distance below that exit port]. This divergence may be considerablyless than that projected from the hollow collimators. However, thedivergence produced in a plane parallel to the length of the cylinderlens will be substantially equal to that projected from the hollowcollimators because the lens has no power in that plane.

[0097] Each sawtooth element receives light from an exit port apertureover a small angular range. This range is approximately equal to the arctangent of [the width of the aperture times the cosine of the sawtoothfeature's line-of-sight angle relative to vertical (as seen from theaperture center) and divided by the line-of-sight distance between theaperture center and the sawtooth feature]. This angular range is, aspreviously mentioned, in planes normal to the length direction of thesawtooth features. As in the case of collimation by the cylinder lens,the angular divergence range in the orthogonal planes (parallel to thesawtooth feature length) will be substantially equal to that projectedfrom the hollow collimators owing to the lenticular nature of thesawtooth features.

[0098] Bottom Surface Diffusion Action:

[0099] The bottom diffusing surface of the collimator and diffuserelement can be lenticularly rippled as shown in FIGS. 14 and 16. Theripples are designed to spread the collimated light projected downwardfrom collimating features on the top surface over an angle of β shown inFIG. 14 after emerging from the rippled surface. The spreading (ordiffusing) action takes place in planes normal to the lenticularripples. The shape of the ripples can control the angular distributionof light within the limits of β. For example, the ripples can besinusoidally shaped, or they may a series of convex or concavecylindrical protrusions or depressions, or they may be a series ofalternating convex/concave cylinders. And, of course, other lenticularripple shapes are possible. Each option has its own characteristicangular distribution within β. The magnitude of p increases withincreasing amplitude-to-pitch ratio of the ripples. The shape,amplitude, and pitch parameters of the ripples are design choices.

[0100] Alternative Collimation or Diffusion Methods:

[0101] Those skilled in the art can apply other collimation or diffusiontechniques known in the art, such as means using holographic or binaryoptical sciences.

[0102] Implementations using Different Lamp Types:

[0103] It is noted that the present invention can be modified toaccommodate lamp types other than tubular fluorescent lamps. Forinstance, the present invention can also be used with lamps havingcompact light-emitting elements such as lamps with tungsten filaments,short arc high intensity discharge lamps, or lamps of the ceramic metalhalide (CMH) type. Such lamps are nearer to being point sources thantubular fluorescent lamps and therefore require luminaire designs thathave substantial radial symmetry around the emitting element rather thandesigns of a lenticular nature.

[0104] For example a luminaire in accordance with the present inventioncan be designed to accommodate the CMH lamps such as the well-knownTD-7, T-4, T-6, ED-17 and ED-18 bulbs, which have an extraordinarilyhigh luminous efficiency. For these lamps, the cusp up-light reflectorof the luminaire is a surface of revolution about the vertical axisthrough the center of the CMH lamp's light-emitting element. A singlehollow collimator below the light-emitting element can have taperedcross-sections that are square, rectangular (near square), circular,elliptical (near circular), or a mix of these cross-sectional shapes.The collimator/diffuser element below the hollow collimator element exitport aperture preferably has a cross-sectional shape that is radiallysymmetric about the vertical axis through the center of the CMH lamp'slight-emitting element. Accordingly, the lens on the top surface of anassociated collimator/diffuser element 320 preferably has a sphericalrather than a cylindrical shape, the sawtooth features on the topsurface have conical rather than lenticular surfaces, and thelight-diffusing ripples on the bottom surface are radially symmetricabout the lens axis rather than lenticular.

[0105] Alternative Shapes of the Collimating Lens in the Center of theTop Surface:

[0106] For superior collimation performance by avoidance of sphericalaberration, the center lens can be aspheric rather than spherical.Alternatively, it can be a conventional fresnel lens. The latter willhave some scattering light losses from the non-collimating fresnel lensfacets between adjacent collimating fresnel lens facets.

[0107] For lenticular embodiments of this invention, the sphere will bea two-dimensional uniform lenticular cross-section and the fresnel lenswill be a lenticular type.

[0108] Fresnel lenses have the advantage of greater compactness andlower weight than the spherical, cylindrical, and aspheric lensalternatives.

[0109] Luminaire Array Options:

[0110] The luminaire embodiments disclosed herein can be arranged inpatterns of multiple units. For example, implementations with tubularfluorescent lamps can be arranged in a radial configuration of unitsthat resemble the spokes of a wheel. Alternatively, they can be arrangedin a linear array of multiple units with the array direction normal tothe lenticular luminaire direction. For very large areas requiringillumination, they can be arranged in a rectangular array of n by mmultiple units, where n and m are positive integers. Similarly,embodiments with lamps having compact light-emitting elements can alsobe arranged in linear array fashion or in rectangular array fashion.

[0111] Fabrication Options:

[0112] The collimator/diffuser element is preferably made from anoptically clear refractive medium such as glass or plastic to maintainlow light absorption losses. Plastics such as acrylic, polycarbonate,polystyrene, and topas are options.

[0113] The top and bottom surface features can be produced by mechanicalcutting methods, or they may be molded. Another alternative would be togenerate the top or bottom surface features separately on a thinsubstrate or roll of material that can be laminated to a substrate.

[0114] Circular Bulbs

[0115] T5 circular bulbs are now also available and are becomingincreasingly popular. FIG. 17 shows how one possible configuration foraccommodating such bulbs. FIG. 17 is a view of the luminaire as it wouldbe seen from above (i.e., from the ceiling). The inner and outer circlesrepresent an upward-reflecting cusp mirror 500 that has a substantiallyradial symmetry around the vertical. Circular lamp 101 with electricalconnector 102 is suspended within the channel of mirror 500. A pluralityof downward pointing collimators 110 are arranged immediately below bulb101 such that light emanating from bulb 101 passes directly throughcollimators 110 or is reflected off of mirror 500 as described above.

[0116] Third Embodiment

[0117] A third embodiment of the present invention, depicted in FIG.18A, is a luminaire that includes lamps 100, curved reflectors 105,collimators 110 and a single solid waveguide 801 associated With eachcollimator and lamp combination that preferably has a sawtooth patternon an angled side thereof, as shown in FIG. 18B. The sawtooth pattern isused in the same manner as the serially-arranged TIR components alreadydescribed in the sense that a portion of the light that enters solidwaveguide 801 totally internally reflects at each facet thereof. Leakagethrough a given facet is picked-up by successive facets. Remainingleakage is redirected back through the facets as desired using aspecular reflector 805.

[0118] Advantages of the light guides shown in FIG. 18A include theability to distribute light over a large exit area, and to maintain athin cross sectional appearance for enhanced aesthetic appeal.

[0119] Fourth Embodiment

[0120] The fourth embodiment of the present invention is directed to aluminaire that comprises a hollow cavity. FIG. 19 illustrates aluminaire that includes lamps 100, curved reflectors 105, collimators 10and a hollow cavity 901. At top and side portions of hollow cavity 901are reflectors 905 that redirect light towards extraction features. Asshown in FIG. 19, the extraction feature is preferably an uncoatedsawtooth film 910. An apical angle of the sawtooth can vary along thelength of the waveguide. In variants not shown in FIG. 19, reflectors905 include microstructures features and TIR structures can beinterspersed with the sawtooth film to guide more light further down thewaveguide.

[0121] Some differences between the previous embodiments and this fourthembodiment include:

[0122] Hollow cavity waveguide vs. solid waveguide;

[0123] Prismatic film on the bottom of an un-tapered waveguide (asopposed to sawtooth features on the top surface of a tapered solidwaveguide);

[0124] Varying the sawtooth angles along the length of the prismaticfilm;

[0125] Interspersing TIR features with the sawtooth features; and

[0126] Including microstructure features on the top and end reflectors.

[0127] Fifth Embodiment

[0128] A fifth embodiment of the present invention is directed toimproving the efficiency of a hollow cavity luminaire like that of thefourth embodiment. In this embodiment, depicted in FIG. 20, a refractiveslab 1001 is inserted into a hollow waveguide cavity to “push” lightflux further down the guide prior to extraction. Slab 1001 is preferablycomprised of acrylic, but may be manufactured from any refractivematerial having high optical clarity and which can be molded,mechanically ground and polished, or diamond turned to provide thedesired dimensions and surface smoothness. This embodiment providessuperior luminance uniformity over the full length of the waveguide.

[0129] More specifically, moving more light down the waveguide (i.e.,hollow cavity 1003) through slab 1001, enhances uniformity of luminanceacross the bottom light output surface of the waveguide. Preferably,this bottom output surface comprises a sawtooth film sheet 1007 made of,for example, polycarbonate material. The enhanced uniformity, along withthe sawtooth film, adds aesthetic value and reduces glare fromilluminated objects. In some applications it may be desirable to add aplurality of slabs of different lengths and thicknesses, therebyproviding significant performance improvement while minimizing thevolume of slab material required. Of course, it is recognized thatminimizing slab material volume is important for reducing cost.

[0130] It should be recognized that individual features described withrespect to specific embodiments may be combined with other embodimentsto achieve alternate configurations.

[0131] The foregoing disclosure of the preferred embodiments of thepresent invention has been presented for purposes of illustration anddescription. It is not intended to be exhaustive or to limit theinvention to the precise forms disclosed. Many variations andmodifications of the embodiments described herein will be apparent toone of ordinary skill in the art in light of the above disclosure. Thescope of the invention is to be defined only by the claims appendedhereto, and by their equivalents.

[0132] Further, in describing representative embodiments of the presentinvention, the specification may have presented the method and/orprocess of the present invention as a particular sequence of steps.However, to the extent that the method or process does not rely on theparticular order of steps set forth herein, the method or process shouldnot be limited to the particular sequence of steps described. As one ofordinary skill in the art would appreciate, other sequences of steps maybe possible. Therefore, the particular order of the steps set forth inthe specification should not be construed as limitations on the claims.In addition, the claims directed to the method and/or process of thepresent invention should not be limited to the performance of theirsteps in the order written, and one skilled in the art can readilyappreciate that the sequences may be varied and still remain within thespirit and scope of the present invention.

What is claimed is:
 1. A luminaire, comprising: a light waveguide; acollimator mounted adjacent the waveguide and operable to pass light toan input end of the waveguide; a lamp located on a side of thecollimator opposite to that of the waveguide such that at least somelight emanating from the lamp passes through the collimator and entersthe waveguide; and a plurality of serially-arranged total internalreflection (TIR) components arranged within the waveguide, wherein atleast some light that passes through the collimator enters the waveguideand is cast upon a first one of the serially-arranged TIR componentssuch that at least a first portion of the at least some light isdeflected toward an output side of the waveguide, and wherein a secondportion of the light that falls upon the first one of theserially-arranged TIR components, but defeats total internal reflectioncharacteristics of that first TIR component, is cast upon a second oneof the serially-arranged TIR components and is deflected toward theoutput side of the waveguide.
 2. The luminaire of claim 1, wherein theoutput side of the waveguide is oriented downward when the luminaire ismounted near a ceiling.
 3. The luminaire of claim 1, wherein thecollimator is one of a hollow collimator and a solid collimator.
 4. Theluminaire of claim 1, further comprising a reflector adjacent thecollimator and proximate the lamp.
 5. The luminaire of claim 1, whereinthe reflector is one of curved and multi-faceted.
 6. The luminaire ofclaim 1, further comprising a refracting medium disposed between thereflector and the lamp.
 7. The luminaire of claim 6, further comprisinga light pipe disposed adjacent the refracting medium.
 8. The luminaireof claim 1, wherein the serially-arranged TIR components compriseprisms.
 9. The luminaire of claim 8, wherein the prisms are integrallyformed with one another.
 10. The luminaire of claim 1, wherein theserially-arranged TIR components comprise sawtooth waveguides.
 11. Theluminaire of claim 1, wherein the waveguide is at least partiallyenclosed in a specular enclosure.
 12. The luminaire of claim 1, whereinthe collimator is arranged to pass light substantially horizontally tothe waveguide.
 13. The luminaire of claim 1, wherein the lamp is hiddenfrom direct view.
 14. The luminaire of claim 1, further comprising ahangar.
 15. The luminaire of claim 1, wherein light that emanates fromthe luminaire is in compliance with ISO 5035/7.
 16. A luminaire,comprising: a light waveguide having an input and an output and definingan interior space, the interior space of the waveguide comprising aplurality of serially-arranged total internal reflection (TIR)components, wherein an input side of a first one of theserially-arranged TIR components is adjacent to the input of thewaveguide; a collimator having an input side and an output side, theoutput side of the collimator being in optical communication with theinput of the waveguide and the first one of the serially-arranged TIRcomponents; a reflector arranged adjacent the input side of thecollimator; and a lamp, wherein light that passes through the collimatorenters the input of the waveguide and is cast upon the first one of theserially-arranged TIR components such that at least a first portion ofthe light is deflected toward the output of the waveguide, and wherein asecond portion of the light that is cast upon the first one of theserially-arranged TIR components, but defeats total internal reflectioncharacteristics of that first TIR component, is cast upon a second oneof the serially-arranged TIR components and is deflected toward theoutput of the waveguide.
 17. The luminaire of claim 16, wherein thereflector is one of curved and multi-faceted.
 18. The luminaire of claim16, further comprising a refracting medium disposed between thereflector and the lamp.
 19. The luminaire of claim 18, furthercomprising a light pipe disposed adjacent the refracting medium.
 20. Theluminaire of claim 16, wherein the output side of the waveguide isoriented downward when the luminaire is mounted near a ceiling.
 21. Theluminaire of claim 16, wherein the collimator is one of a hollowcollimator and a solid collimator.
 22. The luminaire of claim 16,wherein the serially-arranged TIR components comprise prisms.
 23. Theluminaire of claim 22, wherein the prisms are integrally formed with oneanother.
 24. The luminaire of claim 16, wherein the serially-arrangedTIR components comprise sawtooth waveguides.
 25. The luminaire of claim16, wherein the waveguide is at least partially enclosed in a specularenclosure.
 26. The luminaire of claim 16, wherein the collimator isarranged to pass light horizontally to the waveguide.
 27. The luminaireof claim 16, wherein the lamp is hidden from direct view.
 28. Theluminaire of claim 16, further comprising a hangar.
 29. The luminaire ofclaim 16, wherein light that emanates from the luminaire is incompliance with ISO 5035/7.
 30. A luminaire, comprising a lamp; acollimator arranged under the lamp when the luminaire is installed foruse; and a side reflector surrounding at least a portion of thecollimator.
 31. The luminaire of claim 30, further comprising a sidereflector surrounding at least a portion of the lamp.
 32. The luminaireof claim 31, wherein the side reflector surrounding at least a portionof the lamp is in line with the side reflector surrounding at least aportion of the collimator.
 33. The luminaire of claim 31, wherein theside reflector surrounding at least a portion of the lamp is angled withrespect to the side reflector surrounding at least a portion of thecollimator.
 34. The luminaire of claim 30, further comprising arefractive medium disposed between the side reflector and the lamp. 35.The luminaire of claim 34, further comprising a light pipe disposedadjacent the refractive medium.
 36. The luminaire of claim 30, furthercomprising a light control structure disposed between the lamp and thecollimator.
 37. The luminaire of claim 30, further comprising a lightcontrol film disposed near an output end of the collimator.
 38. Theluminaire of claim 37, wherein the light control film comprises adiffuser screen.
 39. The luminaire of claim 37, wherein the lightcontrol film comprises vertical light input facets and hypotenusefacets.
 40. The luminaire of claim 39, wherein an angle of adjacenthypotenuse facets is different.
 41. The luminaire of claim 37, whereinthe light control film comprises a lens.
 42. The luminaire of claim 41,wherein the lens has a focal length that is substantially equal to adistance between the lens and an output end of the collimator.
 43. Theluminaire of claim 37, wherein the light control film is operable tocollimate and diffuse light.
 44. The luminaire of claim 37, wherein thelight control film is disposed at a predetermined distance from theoutput end of the collimator.
 45. The luminaire of claim 30, wherein theside reflector is at least one of a curved reflector and a multi-facetedreflector.
 46. The luminaire of claim 30, wherein the luminairecomprises a plurality of modular luminaire units.
 47. The luminaire ofclaim 30, wherein the lamp comprises an arc lamp.
 48. The luminaire ofclaim 30, wherein a geometry of said side reflector is formed topreclude redirecting lamp flux back onto the lamp.
 49. A modularluminaire component, comprising: a collimator; and a cusped reflectorsurrounding the collimator, a first portion of a cusp of the cuspedreflector being disposed on one side of the collimator and a secondportion of the cusp of the cusped reflector being disposed on anotherside of the collimator, wherein an input end of the collimator and thefirst and second portions of the cusp are in substantial alignment witheach other.
 50. The luminaire component of claim 49, wherein the cuspedreflector is multi-faceted.
 51. The luminaire component of claim 49,having an overall efficiency of at least 95%.
 52. The luminairecomponent of claim 49, wherein a plurality of components are arranged ina straight line.
 53. The luminaire component of claim 49, wherein aplurality of components are arranged in the shape of a circle.
 54. Aluminaire section, comprising: a hollow collimator; and a cuspedreflector, the cusped reflector having a surface through which isprovided an opening that is sufficiently large to allow at least aportion of the hollow collimator to pass therethrough, the opening beingpositioned symmetrically about a cusp of the cusped reflector.
 55. Theluminaire section of claim 54, wherein the cusped reflector ismulti-faceted.
 56. The luminaire section of claim 54, having an overallefficiency of at least 95%.
 57. The luminaire section of claim 54,wherein a plurality of sections are arranged in a straight line.
 58. Theluminaire section of claim 54, wherein a plurality of sections arearranged in the shape of a circle.
 59. A luminaire, comprising: a lampgenerating luminous flux; at least one collimator arranged adjacent tothe lamp; and a side reflector adjacent to the lamp and the at least onecollimator, wherein said at least one collimator directs a portion ofsaid flux in a first direction and said side reflector directs a largerportion of said flux in a direction that is different from said firstdirection.
 60. The luminaire of claim 59, wherein said side reflector isa cusp-shaped reflector surrounding a portion of the lamp.
 61. Theluminaire of claim 60, further comprising a second side cusp-shapedreflector surrounding another portion of the lamp.
 62. The luminaire ofclaim 61, wherein said at least one collimator receives flux fromapertures between said side reflectors.
 63. A luminaire, comprising alamp; a collimator arranged under the lamp when the luminaire isinstalled for use; and a collection of total internal reflection (TIR)components arranged beneath the collimator when the luminaire isinstalled for use.
 64. The luminaire of claim 63, wherein the collectionof TIR components arranged beneath the collimator comprises a firstprism arranged with its hypotenuse oriented downward and at least twoprisms adjacent the first prism with their respective hypotenusesoriented upward such that light that passes through the collimatorenters the first prism and is reflected towards a first one of the atleast two prisms whereupon at least a first portion of that light isdeflected downward and whereupon a second portion of that light defeatstotal internal reflection characteristics of the first one of the atleast two prisms and is cast upon a second one of the at least twoprisms whereupon the second portion of the light is deflected downward.65. The luminaire of claim 64, further comprising a pair of a collectionof total internal reflection (TIR) components arranged beneath thecollimator when the luminaire is installed for use, the pair beingarranged in a mirror-like fashion.
 66. The luminaire of claim 65,wherein first prisms of each one of the pair of collection of TIRcomponents are arranged to completely overlap an output end of thecollimator.
 67. The luminaire of claim 65, wherein first prisms of eachone of the pair of collection of TIR components are arranged topartially overlap an output end of the collimator.
 68. A luminaire,comprising: a lamp; a collimator arranged adjacent the lamp; a solidlight waveguide arranged on an opposite side of the collimator from thelamp, the solid waveguide comprising a sawtooth pattern on an angledside thereof; and a specular reflector disposed above the angled side ofthe solid waveguide.
 69. The luminaire of claim 68, further comprising areflector that at least partially surrounds the lamp.
 70. The luminaireof claim 68, further comprising a hangar for hanging the luminaire froma ceiling.
 71. A luminaire, comprising: a lamp; a collimator arrangedadjacent the lamp; and a hollow light waveguide arranged on an oppositeside of the collimator from the lamp, wherein an output side of thewaveguide comprises an uncoated sawtooth film and wherein an apicalangle of the sawtooth feature of the uncoated sawtooth film varies alonga length of the waveguide.
 72. The luminaire of claim 71, furthercomprising at least one reflector.
 73. The luminaire of claim 71,further comprising a hangar for hanging the luminaire from a ceiling.74. The luminaire of claim 71 , further comprising a refractive slabdisposed within the waveguide.
 75. The luminaire of claim 74, whereinthe refractive slab is comprised of acrylic.
 76. An edge-illuminatedhollow light guide, comprising: a refractive slab light guide fortransporting light from one portion of said hollow light guide forrelease at another portion.
 77. The edge-illuminated hollow light guideof claim 76, wherein said slab has an edge in proximity to an edge ofthe hollow light guide